Filter

Refine by date

—

Refine by access

  • Print
  • Save

Search Results

You are looking at 1 - 1 of 1 items for

  • Author: Renata P Rocha x
  • Refine by access: Content accessible to me x
Clear All Modify Search
Andrea C F Ferreira Laboratório de Fisiologia Endócrina, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil

Search for other papers by Andrea C F Ferreira in
Google Scholar
PubMed Close
,
Lívia P Lima Laboratório de Fisiologia Endócrina, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil

Search for other papers by Lívia P Lima in
Google Scholar
PubMed Close
,
Renata L Araújo Laboratório de Fisiologia Endócrina, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil

Search for other papers by Renata L Araújo in
Google Scholar
PubMed Close
,
Glaucia Müller Laboratório de Fisiologia Endócrina, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil

Search for other papers by Glaucia Müller in
Google Scholar
PubMed Close
,
Renata P Rocha Laboratório de Fisiologia Endócrina, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil

Search for other papers by Renata P Rocha in
Google Scholar
PubMed Close
,
Doris Rosenthal Laboratório de Fisiologia Endócrina, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil

Search for other papers by Doris Rosenthal in
Google Scholar
PubMed Close
, and
Denise P Carvalho Laboratório de Fisiologia Endócrina, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil

Search for other papers by Denise P Carvalho in
Google Scholar
PubMed Close

Transport of iodide into thyrocytes, a fundamental step in thyroid hormone biosynthesis, depends on the presence of the sodium–iodide symporter (NIS). The importance of the NIS for diagnosis and treatment of diseases has raised several questions about its physiological control. The goal of this study was to evaluate the influence of thyroid iodine content on NIS regulation by thyrotrophin (TSH) in vivo. We showed that 15-min thyroid radioiodine uptake can be a reliable measurement of NIS activity in vivo. The effect of TSH on the NIS was evaluated in rats treated with 1-methyl-2-mercaptoimidazole (MMI; hypothyroid with high serum TSH concentrations) for 21 days, and after 1 (R1d), 2 (R2d), or 5 (R5d) days of withdrawal of MMI. NIS activity was significantly greater in both MMI and R1d rats. In R2d and R5d groups, thyroid iodide uptake returned to normal values, despite continuing high serum TSH, possibly as a result of the re-establishment of iodine organification after withdrawal of MMI. Excess iodine (0.05% NaI for 6 days) promoted a significant reduction in thyroid radioiodide uptake, an effect that was blocked by concomitant administration of MMI, confirming previous findings that iodine organification is essential for the iodide transport blockade seen during iodine overload. Therefore, our data show that modulation of the thyroid NIS by TSH depends primarily on thyroid iodine content and, further, that the regulation of NIS activity is rapid.

Article Type:
Research Article
DOI:
https://doi.org/10.1677/joe.1.05643
Volume/Issue:
Volume 184: Issue 1
Free access